export const downloadFile = (fileName: string, blob: Blob) => {
  const blobUrl = URL.createObjectURL(new Blob([blob]));
  //创建a标签
  let link = document.createElement("a");
  link.href = blobUrl;
  link.download = fileName || "下载文件";
  document.body.appendChild(link);
  link.click(); //点击下载
  link.remove(); //下载完成后移除元素
};
